Therapeutic pipeline for soft-tissue sarcoma

The role of pazopanib on tumour angiogenesis and in the management of cancers: A review

Pazopanib is a relatively new compound to be introduced into the chemotherapy field. It is thought to have decent anti-angiogenic properties, which gives an additional hope for the treatment of certain types of cancers. A systematic review solely discussing about pazopanib and its anti-angiogenic effect is yet to be published to date, despite several relevant clinical trials being conducted over the recent years. In this review, we aim to investigate the mechanism of pazopanib's anti-angiogenic effect and its effectiveness in treating several cancers. We have included, in this study, findings from electronically searchable data from randomized clinical trials, clinical studies, cohort studies and other relevant articles. A total of 352 studies were included in this review. From the studies, the effect of pazopanib in various cancers or models was observed and recorded. Study quality is indefinite, with a few decent quality articles. The most elaborately studied cancers include renal cell carcinoma, solid tumors, advanced solid tumors, soft tissue sarcoma, breast cancer and gynecological cancers. In addition, several less commonly studied cancers are included in the studies as well. Pazopanib had demonstrated its anti-angiogenic effect based on favorable results observed in cancers, which are caused by angiogenesis-related mechanisms, such as renal cell carcinoma, solid tumors, advanced solid tumors and soft tissue sarcoma. This review was conducted to study, analyze and review the anti-angiogenic properties of pazopanib in various cancers. The results obtained can provide a decent reference when considering treatment options for angiogenesis-related malignancies. Furthermore, the definite observations of the anti-angiogenic effects of pazopanib could provide newer insights leading to the future development of drugs of the same mechanism with increased efficiency and reduced adverse effects.

Advances in the targeted therapy of liposarcoma

Liposarcoma (LPS) is the most common type of soft-tissue sarcoma. Complete surgical resection is the only curative means for localized disease; however, both radiation and conventional cytotoxic chemotherapy remain controversial for metastatic or unresectable disease. An increasing number of trials with novel targeted therapy of LPS have provided encouraging data during recent years. This review will provide an overview of the advances in our understanding of LPS and summarize the results of recent trials with novel therapies targeting different genetic and molecular aberrations for different subtypes of LPS.

The off-label use of targeted therapies in sarcomas: the OUTC'S program

Background

Few targeted therapies (TTs) are registered for sarcoma treatment despite numerous phase II studies and yet there are potential treatment options for patients after standard treatment escape. The French Sarcoma Group - Bone Tumor Study Group (GSF-GETO) created a national registry to evaluate the outcome of patients treated with off-label TTs.

Methods

Every consecutive sarcoma-patient receiving an off-label TT outside a clinical trial was included. The objective was to describe this patient efficacy and safety data in routine practice.

Results

From October 2008 to October 2011, 249 patients in 24 centers received 278 treatment lines with TTs. Twenty-five histological subtypes were included: most frequent were leiomyosarcoma (n = 48, receiving sorafenib in 63%, and sunitinib in 27%), GIST (n = 39, receiving sorafenib in 79%), and angiosarcoma (n =18, receiving sorafenib in 78%). The overall response rate to TTs was 15% (95% CI [10,6-20,2]), the disease control rate at 2 months was 59%. The median progression-free survival was 4,1 months (IC 95% [3,2-4,8]). Three complete responses were observed. No toxic death occurred, grade 3 and 4 toxicities were reported in 74 (27%) and 14 patients (5%) respectively.

Conclusion

Off-label TTs can be used for sarcoma patients in routine practice with an acceptable toxicity profile and efficacy similar to that reported in non-randomized clinical trials.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-870) contains supplementary material, which is available to authorized users.

Cost effectiveness of first-line treatment with doxorubicin/ifosfamide compared to trabectedin monotherapy in the management of advanced soft tissue sarcoma in Italy, Spain, and sweden

Background. Doxorubicin/ifosfamide is a first-line systemic chemotherapy for the majority of advanced soft tissue sarcoma (ASTS) subtypes. Trabectedin is indicated for the treatment of ASTS after failure of anthracyclines and/or ifosfamide; however it is being increasingly used off-label as a first-line treatment. This study estimated the cost effectiveness of these two treatments in the first-line management of ASTS in Italy, Spain, and Sweden. Methods. A Markov model was constructed to estimate the cost effectiveness of doxorubicin/ifosfamide compared to trabectedin monotherapy, defined as the cost per QALY gained, in each country. Results. First-line treatment with doxorubicin/ifosfamide resulted in lower two-year healthcare costs and more QALYs than first-line treatment with trabectedin monotherapy in all three countries. Probabilistic sensitivity analysis showed that at a cost per QALY threshold of €35,000, >90% of a cohort would be cost effectively treated with doxorubicin/ifosfamide compared to trabectedin monotherapy in all three countries. Conclusion. Within the model's limitations, first-line treatment of patients with ASTS with doxorubicin/ifosfamide instead of trabectedin monotherapy affords a cost-effective use of publicly funded healthcare resources in Italy, Spain, and Sweden and is therefore the preferred treatment in all three countries. These findings support the recommendation that trabectedin should remain a second-line treatment.

Do our current clinical trial designs help to guide clinical practice?

There is a markedly increasing contrast between the current refinement of nosologic classification of sarcoma integrating molecular typing with a growing number of subtypes and the usually standardized approach proposed in clinical practice guidelines for both local and systemic treatment. Although gastrointestinal stromal tumor (GIST), dermatofibrosarcoma protuberans, and a few other subtypes now have specific therapeutic strategies, the majority of sarcomas are still lumped together in clinical trials investigating novel therapeutic options. These trials may not provide sufficient information to guide routine clinical practice. Proof-of-concept trials exploring a targeted agent in a selected molecular subtype, randomized phase II trials, and trials focusing on histologic subtypes-all integrating translational research and aiming to identify the mechanisms of sensitivity and resistance to the treatment-are needed. This paper discusses the limitations of previous clinical trial designs to guide clinical practice in this complex context.

Pazopanib for the treatment of soft-tissue sarcoma

Pazopanib is a multikinase inhibitor which potently inhibits the activity of major receptor tyrosine kinases, including vascular endothelial growth factor receptor-1, vascular endothelial growth factor receptor-2, vascular endothelial growth factor receptor-3, platelet-derived growth factor receptor-a, platelet-derived growth factor receptor-a, and c-Kit. Approved by the Food and Drug Administration in 2009 in the United States for the treatment of metastatic renal cell carcinoma, pazopanib has been tested in advanced or metastatic soft-tissue sarcoma. Unlike other tyrosine kinase inhibitors, a statistically significant efficacy in phase II but also in randomized phase III studies has been shown. In comparison with sunitinib or sorafenib, pazopanib has a similar toxicity profile and is generally well tolerated. This review details the development of this new therapeutic class in the treatment of metastatic soft-tissue sarcomas.

New therapeutic targets in soft tissue sarcoma

Soft tissue sarcomas are an uncommon and diverse group of more than 50 mesenchymal malignancies. The pathogenesis of many of these is poorly understood, but others have begun to reveal the secrets of their underlying mechanisms. With considerable effort over recent years, soft tissue sarcomas have increasingly been classified on the basis of underlying molecular alterations. In turn, this has allowed the development and application of targeted agents in several specific, molecularly defined, sarcoma subtypes. This review will focus on the rationale for targeted therapy in sarcoma, with emphasis on the relevance of specific molecular factors and pathways in both translocation-associated sarcomas and in genetically complex tumors. In addition, we will address some of the early successes in sarcoma-targeted therapy as well as a few challenges and disappointments in this field. Finally, we will discuss several possible opportunities represented by poorly understood, but potentially promising new therapeutic targets, as well as several novel biological agents currently in preclinical and early phase I/II trials. This will provide the reader with the context for understanding the current state of this field and a sense of where it may be headed in the coming years.